Adrenocortical carcinoma (ACC) is a highly malignant tumor with an incidence of 1 to 1.6 cases per million per year. It presents with metastatic disease in up to 40% of cases. In advanced or recurrent disease treatment options are limited, and therapies using agents such as mitotane, cisplatin and adriamycin effect a tumor response rate of less than 30%. Pheochromocytomas have emerged as an endocrine malignancy with few options but with promising targets and very interesting genetics and these are being pursued. Finally, thyroid carcinoma is the most common endocrine malignancy, accounting for the majority of deaths from endocrine cancers. Each year in the US, approximately 14,000 new cases of thyroid carcinoma are diagnosed and 1200 patients die from this disease. Conventional therapy consists of surgical resection and radioiodine (131I) therapy. However, for poorly differentiated thyroid carcinomas (PDTCs) and anaplastic carcinomas that do not concentrate iodine, 131I therapy is ineffective. In these patients, therapeutic options are few and largely ineffective. In adrenocortical cancer we are pursuing strategies that will hopefully lead to targeted therapies. We have been interested in novel chemotherapeutic agents that are toxic to the normal adrenal gland and have been working to identify the steps in the normal adrenal that might be responsible for activating compounds that might otherwise not be cytotoxic. The expression of unique enzymes as part of the steroid biosynthetic pathway are likely candidates, and we have identified in adrenal cancers, a high percentage that express levels of the enzymes that are comparable to those in the normal adrenal. We are pursuing a compound that is toxic to the normal adrenal based on this information. We are also seeking to identify strategies to modulate the expression of these genes in adrenal cancers, with the goal of up-regulating the expression of crucial enzymes so as to render the adrenal cancers vulnerable to these compounds. Finally we are pursuing genetic and expression analyses to better understand these unique cancers and their diverse biology.Pheochromocytomas present a very rare disease with very unique biological and clinical properties and with increasingly complex and puzzling genetics. We are pursuing clinical strategies that will hopefully lead to better therapies and better inderstanindg of how our therapie work and preclinical and laboratory studies to better understand the biology of cancers driven by mutations in the SDHB gene.In thyroid cancer we are expanding our effort to a basic/translational/clinical program that aims to help understand the mechanism of action of novel agents, and their targets in thyroid malignancies. We have begun this effort with translational studies aimed at identifying the best way in which to assess the extent of RET inhibition in medullary thyroid carcinomas (MTC) treated with tyrosine kinase inhibitors. Ongoing studies are designed to identify the best way in which to accomplish this are ongoing, and will be supported by the ongoing translational studies. Additional studies will be staring soon in other thyroid histologies, all with translational components. Additionally we are looking at novel/alternate ways to modulate RET expression/function other than the use of TK inhibitors.